Art of extruding cold materials



Aug. 18,1931. J. a. c. MANTLE 1,819,254

ART OF EXTRUDING COLD MATERIALS Filed March 31, 1924 I v @241" .5, 4. ,7 W00 '1 'i '7 15:29.1 J@J5. $5 .1 11: 15. 29.10".

Mania Patented Aug. 18, 1931 aosErH G. c. MAINTLE, or LEONIA, NEW JERSEY AIR-T OF EXTRUDING COLD MATERIALS Application filed march 31,

This invention refers to the extrusion of ,metals in a cold condition, and comprises a method and apparatus by which steel, brass, and similarly hard metals, can be extruded without preliminary heatin to soften the same. Hitherto, only the so er metals,'such as lead or tin, and other soft materials, could be extruded without softening by heat. Moreover, in many instances where certain 1 harder metals could beextruded by preliminary heating it was found more economical, on account of the slowness and cost of the operation, to machine the cold material rather than extrude it. v I

In the drawings,- Figure 1 is a sectional view of an apparatus for carrying my invention into practice,

with the die, the ram and the punch in the positions they assume at the beginning of the operation.

Figures 2 and 3 are views similar to Figure 1' with the several parts in relative positions as the extrusion pro resses.

Figures 4 to 11, inc usive, are crosssectional views illustrating different forms which may be imparted't'o the material by the procedure and apparatus of my invention.

Figures 12, 13 and 14 are diagrammatic views of the "positions the punch may take relative to the material exit of the die.

Figures 15 and 16 are views of a die and" a punch showing positions wherein the material becomes packed around the punch at the material exit from the die resulting in. a practically inoperative mode of procedure.

Figures 17 to 20, inclusive, are views illustrating in longitudinal section different forms of extruded metal objects. i

' Figure 21 illustrates in longitudinal sec tion and in end elevation another form of extruded metal object, and

Figure 22 is a view similar to Figures 17 to 21 of still another form of metal object.

be made to drawings, more particularly Figures 1,2 and 3.

1 is a piece of non-preheated steel, brass or Iother similarly hard metal and will be called the stock.

In explaining this method reference will .1924. Serial No. 703,060.

2 is a-member for containing the stock to be extruded; it has a corresponding inner form and its size should be such that the stock may slide therein. This member will be called the die.

3 is a member having a cross section, corresponding to, and a closeslidingfit in the die and its use is to push the stock from within the die. This member will be called the ram.

4 is a rod-like member, very hard and strong, and which may have across section of any desired form. This member will be called the punch.'

5 is'a member for holding and supporting the punch. This member will be called the holder,

6' is a member slidably mounted in the holder and having a close sliding-fit in the holder and on or around the punch. Its main use is to steady and support the punch in strict alignment with the die. This member will be called the guide.

7 is a spring for pressing the guide against the extruded stock.

Now suppose the stock 1 to be within the die 2, as shown in Figure 1. The stock may be slid into the die either by withdrawing the die 2 from the holder 5, or, by withdraw ing the ram 3. The rambeing moved in direction towards the punch 4, forces the stock 1 from within the die, against and around the punch, as shown in Figure 2. The further. movement of the ram forces the stock still further around the punch as shown in Figure 3. There need be no pause in this movement of the ram, and its total movement may be a very quick one, for the operation may be performed in a press, or, in a header, or, in other powerful suitable machine. The movement of the ram may continue until there is but a thin. layer of ma; terial between the ram and the punch, as in Figure 3, or, the movement may stop at any time before, .so that this depth of the recess or hollow within the extruded stock is as desired. Stock of any desired crosssection may be extruded, the inner form of the die corresponding to the outer form of the stock,

'see Figures 4' to 10, inclusive, wherein different cross sectional shapes of stock are shown.

With this method when the stock passes from within the die and .around the punch, or, which is the same thing, when the punch is passing into the stock, the outer surface of the stock surrounding the punch is not in contact with the die, and the stock is not surrounded by the die, see Figures 2 and 3; otherwise, if so surrounded, it is not possible, with non-preheated steel, brass or similarly hard metal, for the punch to enter except to a depth amounting to but a fraction of the diameter ofthe punch. In the making of hollow steel set screws many attempts have been made to punch a sufficiently deep recess in the cold metal, but drilling and broaching had to. be resorted to. Even in softer material, such as lead or t'in, the depth of penetration was very limited, this was in great part due tov the material packing and gripping the punch. In this method of operation, not only the outer surface of the material surroundingthe punch is free, but the punch is also free. In fact, during any stage of the operation the stock may be slid from off the punch, or the punch from within the stock.

There may be any desired combination of die and punch cross sections giving any required form of extruded material, the punch being an internal former for imparting the desired internal contour to the product, some of which are shown in Figures site 11, in-.

elusive, and consequently this method of cold extrusion is useful for very varied purposes, for instance, hollow-set-screws, hollow-rivets, shells, tubes, internal gears, socket wrenches, nipples, etc. The cheaper commercial barstock may be used, instead of tubing and sheet material; also it may replace many machine operations such as drilling, drifting, milling,

etc., and avoid much of the scrap.

The form of the free end of the punch and its position relative to the exit of the die affects both the durability of the punch and the outside size of the extruded material. A punch having a rounded or pointed end and a parallel portion appreciably extending into the die, as shown in Figure 15, is useless when dealing with non-preheated steel, brass and similarly hard metals, for the reason that the material packs in the die and grips the punch, and the punch is crippled. The form and position shown in Figure 16 is better, yet the punch is insufficiently durable $31 the operation to be commercially successvThere is far less resistance with a flat ended punch shown in Figures 1, 2, 3, 12 and 13,

With thisform of punch, so positioned, stock varying in size from five to eighteen thousandths of an inch below that of the inside diameter of the die was extruded uniformly of size within two thousandths of an inch of the diameter of the die, and with stock measuring upto four thousandths of an inch below the inside diameter of diethe diameter of the extruded material was within one thousandth of an inch, as also the thickness of the wall surrounding the punch, both transversely and longitudinally, the die thus serving as a former for imparting the desired external size or contour to the product. Also, the outside and inside surfaces were exceedingly smooth, in fact, the inside surface much smoother than could be obtained by internal grinding. Apparently there is a slight packing of the material as it approaches the exit of the die. If the punch is positioned relatively to the exit of the die as in Figure 13, the extruded material has its outside size larger than the inside diameter of the die. If the position of the die be varied relative to the punch (as from that shown in Figure 12 to Figure 13) during the movement of the ram, then the outside sizes of the extruded stock will also vary throughout its length on the punch. Examples-are shown in Figures 17- For Figure 17, the die relative to the punch is as in Figure 13 when the ram commences its stroke and passes to, during, and is as in Figure 12 at the end of the stroke. For Figure 18 it is reversed. For Figure 19 the die relative to ihepunch is as in Figure 12 when the ram commenced its stroke and passes to, during, and is as in Figure 18 at the middle, and returns to as in Figure 12 by the end of the stroke. For Figure 20 it is reversed. For Figure 21 and Figure 22 the die relative to the punch is as in Figure 13 when the ram commences its stroke and after any desired time changes, more or less abruptly as desired, to as in Figure 12 and so remains till the end of the stroke. It is apparent that by such means, a very great variety of outside forms of the extruded material may be obtained. A very convenient way of giving any required movement to the die would be by use of a. cam for each particular form of extruded material similarly as is done in automatic screw-machines. The cam could be given one revolution for each out and return stroke (two strokes) of the ram. The cam could operate one long arm of a lever and a short armof the lever operate the die. The manner of connecting such parts, and the making and applying of such parts are understood by those skilled in the arts to which this invention pertains.

In describing this method, the punch and die has been generally assumed to be stationary and the ram moving, but this is mere-' tionary and the punch and die moving. This ly hard.

may be readily seen by inspection of Figures 1, 2 and 3, assuming the ram as stationary and the movementbeing given to the holder containing the punch.

When using a punch of short length, when a depth of recess of one diameter of the punch, or less,'is required, the guide 6 is not essentiahnevertheless, it is a useful adjunct for it serves as astripper for the extruded stock from the punch. Also it serves to square up or impart other desired shapes to theendof the extruded material, in which case the yieldingfmember 6 is fashioned for that purpose. hen a long punch is used for deep penetration; the guide is necessary to keep the "punch from springing sidewise, especially when the 'st'ockis a loose sliding-fit in the die. extruding such material as steel,bronie ororass, he free or working end of the punchfas' als'o the inside of the die (especially near the exit), must be thorough- Attentionis' directed to Figures 1, be seen that the die 2 punch holder 5.

2 and 3, wherein itf may is sep'arably conriectedto the Onfaccountioffthisseparability, neither the j ioppose die'2 marinade-4 has to slide on or in any part ofthe 'holder *5in order to insert the blankin'to tli die to remove the extrude material irornfth and, as the contacting surfacesoftliefpunch and holder as also the male and female contacting surfaces of the die and holder are slightly conical, they are a11hfi fi entire period of the extrusion, any relative is impossible. Alsojattent is directed to Figure 11 which Shwfifj Section of extruded material the externalfcontour "of which, apart from mere'siae, thatof the blank. To obtain form which is obtained from ank l f; 561.1. t endvf the Punch is positioned in relation to the exit of the die as shownin Figure l3 and not as in Figure 12. As aneaa jherj stated, the IOIIILOf the interror "of fthe die, apart from a slight differways corresponds to that of the new and desire to set is:

for making hollow arf metal a receptacle for extruding material of receptacle, and two mem- "t usion of said'material, rving as an internal of said members yieldr usion during the enitrusion.

for making hollow of metal, a receptacle .c ebylLe U .1 1 an at Met ticles rr'om-b1 are the blank, means theb1ar1jk" f ro.

one, ,oijsard grmri t :1.s,\, .1 "Met-3W a bla'n for extruding materia articles rrom for the blank, means of the blank. from the receptacle, and two members comprlsing an inner member and truded material, and

ate contact that, during the V said material, jacent the said exit during the entire period 1 extrusion and also serving as a an outer member, the extruslon of member serving as an said material, the inner internal former for .said extruding material and theouter memfor the blank, means for extruding material of the blank from the receptacle, a member for the exserving as an internal former truded material, and a lateral-support 1n both members opposing ot metal; a receptacle direct contact with said member durlng the entire period of said extrusion.

4. In'an apparatus for makinghollow articles from a blank of metal, a receptacle for the blank, means for extruding material of the blank from the receptacle, a member serving as an internal former for the ex I a lateral-support adjacent the advancing end of the said extruded material on the said member and also in direct contact with the said member durong the entire period of said extrusion.

5. In an apparatus for making hollow articles from a blank of metal, a receptacle for the blank, means for extruding material of the blank from the receptacle, a member truded material,

extruded material on the said member and also. in sliding contact with the said'member during the entire period of said extrusion.

6. In an apparatus for making hollow articles from a blank of metal, a receptacle for theblank, the receptacle having an exit for the extrusion of material of the blank, means for. extruding the said material through the said exit, a member serving as' an interna former for the extruded material, the said member having a flat end in contact with the and the said flat end being adof said extrusion.

7 In an apparatus for making hollow articles from a blank of metal, a receptacle for the blank, the receptacle having an exitfor the'extrusion of material of the blank, means for extruding the said. material through the said exit, a member serving as an internal former for the extruded material, the said member having a flat end in contact with the said material, and the said fiat end adjacent the said exit and stationary in relation to said exit during the entire period of said extrusion.

'8. In'an apparatus for making hollow articles from a blank of metal, a receptacle for the blank, the receptacle having an exit forthe extrusion of material of the blank, means for extruding the saidmaterial through the said exit, a member yieldably opposing the said lateral-support to, and in direct contact with, a second member during the entire period of the extrusion, the said second member serving as an internal former for the extruded material and ill . blank from the receptacle, a member serving also having an end in contact with the said material and adjacent the said exit during the entire period of said extrusion.

' 9. In an apparatus for making hollow'articles from a blank of metal, a receptacle for the blank, the receptacle having an exit for the extrusion of material of the blank, means for extruding the said material through the said exit, a member yieldably opposing the .said extrusion and serving as a lateral-support to a second member during the entire period of the extrusion, the said second member serving as an internal former for the extruded material and having an end adjacent the said exit and being in contact with the said material, said second member being stationary in relation to said exit during the entire period of said extrusion.

10. In an apparatus for making hollow articles from a blank of metal, a receptacle for the blank, means for extruding material of the blank from the receptacle, a member serving as an internal former for the extruded material, a holder serving as a support and holder for the said member, and a connecting means for separably connecting the said receptacle to the said holder and serving, when connected, to prevent all relative lateral movement of the same.

11. In an apparatus for making hollow articles from a bg'ank of metal, a receptacle for the blank, means for extruding material of the as an internal former for the extruded material, a holder servinglas a support and holder for the said member, and a connecting means for separably connecting the said receptacle to the said holder and serving, when connected, to prevent all relative lateral movement of the same, the said connecting means comprising a male and female surface pressed into contact for the entire period of the said extrusion.

12. In an apparatus of the character described, a receptacle for a blank, means for extruding material of the blank, a stationary member of substantially uniform cross-section and serving as an internal former for the extruded material and having a flat end adjacent said receptacle and a lateral support encircling said former and in sliding contact therewith during the entire period of said extrusion.

13. The method of making tubular'metal articles which comprises positioning a cold metal blank in a confined space, exerting a pressure on one end of the blank so as to cause Y the other end of the blank to be pressed against the fiat end of a stationary punch to extrude the material of the blank into tubular form and exerting a resilient pressure on the end of the extruded material during the entire extruding operation.

14. The method of making tubular metal articles which comprises positioning a cold metal blank in a confined space, exerting a pressure on one end of the blank so as to cause the other end of the blank to be pressed against the end of apunch to extrude the material of the blank into tubular form, varying the position of the punch with respect to the blank during the extruding operation in order to obtain a tubular element having a wall of diiferent thicknesses.

15. The method of making tubular metal articles which comprises positioning a cold metal blank in a confined space, exerting a pressure on one end of the blank so as to cause the other end of the blank to be pressed against the end of a punch to extrude the material of the blank into tubular form, exerting a resilient pressure on the end of the extruded material during the entire extruding operation, and removing the tubular element from the punch by the stored energy of the end resilient pressure.

.16. In an apparatus for making hollow articles from a blank of metal, a receptacle provided with an opening therethrough, a

jacent said opening in said receptacle and adapted to serve as an internal former, a lateral support in sliding contact with said flat ended member, and means for yieldingly pressing said lateral support against the end of the extruded material.

18. In an apparatus fpr making hollow articles from a blank of metal, a receptacle for-the blank and provided with an opening therethrough, a ram fitting within said opening and adapted to extrude material from said receptacle,a former adjacent said opening in said receptacle and having smaller diameter than the said opening, and a lateral support in sliding contact with said former during the extruding operation.

19. hfan apparatus of the character described, a receptacle for a blank of metal, means for extruding material of the blank from the receptacle, a stationary member of substantially uniform cross section and serving as an internal former for the extruded material, and having a flat end adjacent said receptacle, a lateral support encircling said stationary member and in sliding contact therewith during the entire period of said extrusion, and means for yieldingly pressing said lateral support against the end of the 5 extruded material.

In testimony whereof I have hereto signed my name this 26th day of March, 1924. I

. JOSEPH G. C. MANTLE. 

